Wednesday, June 15, 2016

OGLE-2014-BLG-1760b: a Gas Giant Detected Through Micolensing

We present the analysis of the planetary microlensing event OGLE-2014-BLG-1760, which shows a strong light curve signal due to the presence of a Jupiter mass-ratio planet. One unusual feature of this event is that the source star is quite blue, with V−I=1.48±0.08. This is marginally consistent with source star in the Galactic bulge, but it could possibly indicate a young source star in the far side of the disk. Assuming a bulge source, we perform a Bayesian analysis assuming a standard Galactic model, and this indicates that the planetary system resides in or near the Galactic bulge at DL=6.9±1.1 kpc. It also indicates a host star mass of M∗=0.51±0.44M⊙, a planet mass of mp=180±110M⊕, and a projected star-planet separation of a⊥=1.7±0.3AU. The lens-source relative proper motion is μrel=6.5±1.1 mas/yr. The lens (and stellar host star) is predicted to be very faint, so it is most likely that it can detected only when the lens and source stars are partially resolved. Due to the relatively high relative proper motion, the lens and source will be resolved to about ∼46mas in 6-8 years after the peak magnification. So, by 2020 - 2022, we can hope to detect the lens star with deep, high resolution images.